In the printing roller industry, rollers are commonly fabricated of both cast polyurethanes and acrylonitrile rubbers. Each have their place and their particular suitabilities for various ink or other fluid transfer processes.
In the manufacture of rollers there will inevitably be scrap in the way of defective rollers, trimmings, grindings, etc. In addition, as rollers become worn out through use, they are commonly traded in by the printer to the manufacturer. The steel spindle on which the blanket is formed is expensive and reusable. Past practice has been to trim off the worn-out polyurethane blanket and discard it.